Somali troops roll into once rebel bastion of Kismayu, - Hundreds of Somali government troops and allied militia fighters deployed throughout the former al Shabaab rebel stronghold of Kismayu on Monday, sending panicked locals scrambling for cover.

Residents said some soldiers took up
positions on rooftops and that there was no immediate retaliation from the al
Qaeda-linked militants who fled the port city on Friday after Kenyan and Somali
troops launched an assault by sea, air and land.

We have now seen troops walking in
the town. We are running into houses and shops have closed. We are afraid of
explosions," said resident Ismail Nur.

Mohamud Farah,
a spokesman for Somali's army in the southern Juba regions, said 450 government
soldiers and fighters from an allied militia were in the city centre to patrol
the sandy streets and twisting alleyways.

Another
resident, Halima Farah, said Kismayu had turned into a ghost-town. Troops had
occupied the police headquarters building and district administration office,
she said.

"I can
also see through the cracks of windows that some of them are on the rooftops
near those positions," Farah told Reuters by telephone.

Johnnie Carson,
U.S. assistant secretary of state for African affairs, said the recapture of
Kismayu marked "a major step forward" and applauded the military
gains made by the African Union's peacekeeping force in Somalia.

"We
believe this will help to bring about a return to stability in Somalia and will
reduce over time the terrorist threat to Somalis and to neighbouring
states," Carson told reporters on a conference call.

The rebel
group, which counts foreign al Qaeda-trained fighters among its ranks, is seen
as one of the biggest threats to stability in the Horn of Africa. It formally
merged with al Qaeda in February.

Al Shabaab has
said that although it had retreated from Somalia's second biggest city, its
fighters were poised to engage the allied troops once they entered the city
centre, threatening to turn the streets into a "battlefield".

"FALLING
INTO OUR TRAP"

"Their
going in means falling into our trap. Just wait and see what will happen to
them," Sheikh Abdiasis Abu Musab, the spokesman for al Shabaab's military
operation told Reuters.

Kenya's
military used the social media site Twitter to declare its forces had
established no-fire zones around markets, schools, mosques and hospitals.

A Kenyan
military spokesman was not immediately available for comment.

Residents said
it was unclear if Kenyans were in the city centre or still camped out on the
outskirts and were divided over whether the arrival of government forces in the
city was positive.

Winning control
of Kismayu, however, is the easy part, while establishing a political
administration respected by all clans will be much tougher, political analysts
say.

A prolonged
power vacuum in Kismayu might give way to renewed violence as rival groups
jockey for control of the lucrative port in a city where the rebels' strict
application of Islamic law alienated a huge portion of the population.

"(We hope)
the government in Mogadishu ... will go in very quickly and establish political
stability and a political system that takes into account the various clan and
sub-clan interests," Washington's Carson said.

Faiza Mohamed,
a greengrocer, feared a new wave of violence. "We're not
against the government, but Kismayu will become like Mogadishu," she said,
referring to al Shabaab's campaign of suicide bombings and targeted killings
that has swept the capital since the group withdrew from there 14 months ago.

Al Shabaab,
which controlled swathes of south-central Somalia for much of its five-year
rebellion, has increasingly turned to guerrilla tactics as it loses ground
under military pressure.

It was swift to
harass the weak government of newly-elected President Hassan Sheikh Mohamud
with suicide bombings and assassinations.

KENYA ON HIGH
ALERT

Security forces
in Kenya, the region's biggest economy, were on high alert on Monday. Police said
extra roadblocks had been set up on roads leading to neighbouring Somalia,
while a military source said extra surveillance flights were being operated
along the remote, porous frontier.

"Somalia
has been an al Qaeda hideout. You've seen the impact of al Qaeda across the
world and we have just destroyed their backyard," Kenya's deputy police
spokesman Charles Owino told Reuters.

Since it sent
troops into Somalia a year ago, Kenya has been dogged by a succession of gun
and grenade attacks, blamed by the government in Nairobi on al Shabaab and its
sympathisers.

Such low-level
attacks have so far not hurt Kenya's financial markets. However, a
major strike of the kind threatened by al Shabaab on Kenyan government
buildings or sites popular with Western expatriates and holidaymakers would
risk dealing a body-blow to the tourism sector and damaging Kenya's reputation
as a sound investment destination in a volatile region.

The militants
proved their ability to launch a major strike beyond Somalia's frontiers when
suicide bombers killed 79 people in the Ugandan capital, Kampala, in 2010.

(Additional
reporting by Noor Ali in Isiolo and Richard Lough in Nairobi; Writing by
Richard Lough; Editing by James Macharia).